Synchronized network for battery backup

ABSTRACT

Devices, systems, and techniques for a synchronized network for battery backup are described herein. A network device can establish a synchronized sleep schedule with the network while in a mains-power mode of operation. The network device can transmit data in the mains-power mode without regard for a transmission window of the synchronized sleep schedule. The network device can detect an interruption of mains power to itself and transition to a low-power mode of operation. The network device can then transmit data in the low-power mode, restricting data transmission to the transmission window of the synchronized sleep schedule.

BACKGROUND

Wirelessly connected networks of devices can be useful for manyapplications including industrial monitoring and automation. These nodescan be mains powered. At times, however, mains power can fail. Some ofthese nodes can include battery backup in an attempt to bridge suchpower failures. Generally, battery backup capacity is scaled to meet thepower needs of a node while mains power is unavailable.

BRIEF DESCRIPTION OF THE DRAWINGS

In the drawings, which are not necessarily drawn to scale, like numeralsmay describe similar components in different views. Like numerals havingdifferent letter suffixes may represent different instances of similarcomponents. The drawings illustrate generally, by way of example, butnot by way of limitation, various embodiments discussed in the presentdocument.

FIG. 1 illustrates an example of a system of a synchronized network forbattery backup, according to an embodiment.

FIG. 2 illustrates an example of a network device in a synchronizednetwork for battery backup, according to an embodiment.

FIG. 3 illustrates an example of a method to implement a synchronizednetwork for battery backup, according to an embodiment.

FIG. 4 is a block diagram illustrating an example of a machine uponwhich one or more embodiments may be implemented.

DETAILED DESCRIPTION

Using backup batteries for network devices can present a number ofchallenges. For example, batteries can be expensive, increasing unitcost. Also, as battery capacity is increased, there is generally agreater imposition of volume and weight upon the design of the networkdevice. Further, battery capacity is limited, resulting in smallercapacity batteries possibly requiring greater (e.g., more frequent)service time, and thus expense, by an operator. Given theseconsiderations, a small inexpensive battery system is desired whilereducing servicing costs to an operator of the network device. Theseobjectives may be achieved by reducing the power consumption of thenetwork device when mains power is no longer available. In someexamples, other low-power sources, such as photovoltaic devices, may beemployed. However, these systems generally provide less power than mainspower and thus benefit from reduced power consumption as well.

Network device power consumption can be reduced by placing the networkdevice into a low-power state. In an example, this low-power state maybe limited to the transmission or receipt of data to preventinterruption of the network device's monitoring or control functions. Inan example, a sleep coordinator node in the network can assign an activeinterval in which a given network device will be available to transmitdata or be receptive to receive data. In example networks whereindividual network devices have individualized sleep schedules, networkoperation may entail buffering data to be transferred to or through asleeping node. Buffering data in this manner may increase networkcomponent costs due to the added memory used for the buffering. Thisburden may be exacerbated in a decentralized mesh network as each devicemay need to include this increased memory.

An efficient solution to the previously discussed difficulties is asynchronized network for battery backup. When mains power is present,the power requirements of the network device are less important than thenetwork's performance characteristics. Thus, the network device cantransmit during any period in order to achieve high speed or lowerlatency in data transmissions. However, when mains power is unavailablethe network device will use its battery backup. Under thesecircumstances, the network device can operate according to thesynchronized network to reduce power needs and thus extend limit batteryreserves. In this way, network performance is balanced with networkdevice power needs given available power sources.

An example implementation of the synchronized network for battery backupcan include establishing and maintaining a synchronized sleep schedule.The synchronized sleep schedule can be formulated and distributed withinthe network without regard to whether mains power is available to one ormore network devices in the network. The synchronized sleep schedule caninclude a transmission window in which the network device is expected totransmit data. Thus, when mains power is not available, the networkdevice has a reduced duty cycle and requires less power. Accordingly,smaller battery reserves, or less frequent battery tending, is achieved.When mains power is available (e.g., reestablished) to the networkdevice, the network device can transmit during any period without regardto the transmission window in order to achieve greater speed and lowerlatency in data transmissions. By using a synchronized transmissionwindow, network components (e.g., other network devices) will be awareof when data can be transmitted to the network device and expect, ifnecessary, for the network device to pass that data along towards itsfinal destination. Thus, additional memory burdens to buffer networktransmission data can be avoided. By reducing power needs, an operatorcan save costs by using smaller battery reserves and tending to thebatteries less frequently. Additionally, unit costs can be reduced byavoiding unnecessary data buffering. Accordingly, the synchronizednetwork for battery backup can balance network performance whilereducing costs.

FIG. 1 illustrates an example of a system 100 of a synchronized networkfor battery backup. In an example, the system 100 is a synchronizednetwork with synchronized sleep. Example implementation details ofnetworks with synchronized sleep are described in U.S. patentapplication Ser. No. 12/429,358, titled “METHOD FOR SYNCHRONIZINGSLEEPING NODES IN A WIRELESS NETWORK”, filed Apr. 24, 2009, and U.S.patent application Ser. No. 12/429,326, titled “SYSTEM AND METHOD FORADAPTIVELY SETTING THE PROBABILITY OF GENERATING A BEACON BROADCAST IN AWIRELESS NETWORK”, filed Apr. 24, 2009, both of which are hereinincorporated by reference in their entirety.

The system 100 can include a plurality of network devices includingnetwork device 105, network device 110, and network devices 115A-E. Thesystem 100 can also include a synchronized sleep schedule 120. In anexample, the network devices 105-115E can be configured in a meshnetwork. In an example, one or more network devices 105-115E can bewireless.

The synchronized sleep schedule 120 illustrates network device 105-115Etransmission behavior. Each row corresponds to a given network device(e.g., the first row ‘A’ corresponds to the network device A 115A).Shading within a row indicates a time period in which a given networkdevice can transmit. The synchronized sleep schedule 120 includes arepeating transmission window 123 (e.g., an awake window). Asillustrated, a synchronization message 125 is received at each of thenetwork devices 105-115E at the beginning of the transmission window123. In an example, the synchronization message 125 can be received atany time during the transmission window 123. In an example, thesynchronization message 125 can be received at any time. In an example,the synchronization message 125 can include the synchronized sleepschedule 120. In an example, the synchronized sleep schedule 120 caninclude a single set of transmission windows 123 for every networkdevice 105-115E (e.g., every network node) in the network.

The following examples refer to the presence or absence of mains powerfrom the network device 105. As illustrated, mains power is lost to thenetwork device D 105 at period 130. That is, to the left of the period130, the network device D 105 has the benefit of mains power and to theright of period 130 the network device D 105 is operating on batterybackup. As illustrated in FIG. 1, mesh network data traffic canoriginate at a first node, such as network device A 115A, and passthrough other network devices (e.g., the network device D 105) on itsway to its destination (e.g., network device G 115E). The network deviceD 105 can be configured to maintain the synchronized sleep schedule 120without regard to a current power mode (e.g., mains-power or low-power)of itself. The network device D 105 can also be configured to restrictdata transmission (e.g., to the network devices 110 and 115B-C) to thetransmission window 123 when in low-power mode. This behavior isillustrated by the absence of shading in the ‘D’ row to the right ofperiod 130. In an example, the network device D 105 is configured tonotify the network when transitioning to low-power mode.

In an example, the network device B 110, which is configured to transmitdata to the network device D 105, is configured to transition into itslow-power mode in response to a message based on the notification fromthe network device D 105. In an example, the network device B 110 may beconfigured to observe low-power mode transmission requirements to thenetwork device D 105 (e.g., observing the transmission window 123 withrespect to network device D105) while not itself transitioning to thelow-power mode. In this way, the network device B 110 can be assuredthat it will not transmit data to the network device D 105 when networkdevice D 105 is unavailable to transmit, or possibly receive, that data.As illustrated, the network devices A-E 115A-C and 110 have transitionedinto the low-power mode at period 130. This may be due to loss of mainspower in these network devices or as a sympathetic response to the lossof mains power in the network device D 105. In an example, some networkdevices (e.g., network devices F and G 115D-E) do not transition intothe low-power mode. In this example, these network devices can beconfigured to route around a low-power mode device for transmissionsoutside of the transmission window 123. In an example, every networkdevice A-C and E-G 115A-E and 110 is configured to transition tolow-power mode in response to receiving a message based on (e.g.,informing the network device) of network device D's 105 transition tolow-power mode. In an example, every network device A-C and E-G 115A-Eand 110 is configured to observe low-power mode transmissionrequirements to the network device D 105 (e.g., observing thetransmission window 123 with respect to network device D105) while nottransitioning to the low-power mode themselves. In an example, thenetwork is configured to transmit higher priority data during thetransmission window 123. By restricting higher priority data to thetransmission window 123, network performance of the higher priority datais not impacted when one or more network devices A-E 105, 110, 115A-Eare operating in the low-power mode.

FIG. 2 illustrates an example of a network device 200 in a synchronizednetwork for battery backup. The network device 200 can include a networkreceive chain 205, a network transmit chain 210, a power mode detectionmodule 215, a power module 220, a synchronization module 225, and acontroller module 230. The network transmit chain 210 can be configuredto transmit data to the network in which the network device 200 isparticipating. The network receive chain 205 can be configured toreceive data from the network. The network transmit and receive chains210 and 205 can include components such as modulators, encoders,decoders, antennas, mixers, and other signal processing componentsconfigured to transmit data. In an example, one or more of thesecomponents may be shared by the network receive chain 205 and thenetwork transmit chain 210.

The power mode detection module 215 can be configured to determinewhether the network device 200 is operating in a low-power mode or in amains-power mode. In an example, the power mode detection module 215 canbe communicatively coupled to the power module 220 and configured tomonitor one or more indications that mains power is no longer available.In an example, the power mode detection module 215 can be configured tomonitor the source voltage from the power module 220 for a transitionacross a predetermined source voltage threshold to determine theoperating mode. In an example, the power module 220 can be configured tointerface with both mains power and the battery reserve to provide powerto the network device 200. In an example, the power mode detectionmodule 215 can be communicatively coupled to the network receive chain205 and be configured to monitor incoming data for at least one of asleep, wake, or follow-the-synchronized-sleep-schedule-command. That is,the power mode detection module 215 can be triggered to start thetransition from the mains-power mode to the low-power mode and backagain by an external actor on the network. In an example, the power modedetection module 215 can be communicatively coupled to a physicalinterface on the network device 200, such as a button or serial line, towhich a sleep or wake notification can be indicated. In this example, itis therefore possible for an operator to manually transition the networkdevice 200 between the low-power and mains-power modes of operation.

In an example, the power mode detection module 215 can be configured totransition the network device 200 between at least the mains-power modeand the low-power mode based on its determination. In an example, thepower mode detection module 215 can be configured to notify the network,such as a network coordinator or other network participant, of atransition between these power states. Such notification can beconfigured to include details of the transition and permit other networkparticipants to plan accordingly. For example, when the network device200 transitions into the low-power mode the entire network can alsotransition to the low-power or reduced communication (e.g., observingthe transmission window 123) mode. In some instances, transitioningevery network participant into the low-power mode can allow reducedpower consumption without performance degradation. Also, thenotification can alert a network device 200 that will not transition tolow-power mode, but uses the network device 200 as a data destination orintermediary (e.g., router). In this example, the notification permitsthe second network device 200 to formulate a new route or destinationfor its data at least during periods outside of the transmission window123.

The synchronization module 225 can be configured to receive (e.g., viathe network receive chain 205 and store synchronization information. Thesynchronization information can include the synchronized sleep schedule120 for the network. The synchronized sleep schedule 120 can include atransmission window 123. In an example, the synchronized sleep schedule120 is shared with all participants of the network. This sharing entailsthe sharing of the transmission window 123 between the network device200 and other network participants (e.g., network devices) of thenetwork. For example, all network participants may send data during asingle period of time that is the transmission window 123. In anexample, the synchronization module 225 can be configured to acceptsynchronization messages via the network receive chain 205 to facilitatethe establishment (e.g., receipt and storage) of the synchronized sleepschedule 120.

The controller module 230 can be communicatively coupled to any one ormore of the network receive chain 205, the network transmit chain 210,the power mode detection module 215, and the synchronization module 225.The controller module 230 can be configured to transmit data via thenetwork transmit chain 210 without regard to the transmission window 123when the power mode detection module 215 determines that the networkdevice 200 is operating in the mains-power mode. For example, when mainspower is present, the controller module 230 is configured to operate ina high performance (e.g., high data throughput and low data latency)manner.

The controller module 230 can also be configured to restrict datatransmission to the transmission window 123 of the synchronized sleepschedule 120 when the power mode detection module 215 determines thatthe network device 200 is operating in the low-power mode. For example,after loss of mains power, the controller module 230 prevents datatransmissions during periods outside of the transmission window 123 toreduce power consumption. In an example, to restrict data transmission,the controller module 230 is configured to shutdown (e.g., power off)one or more components of its network receive chain 205. In an example,the controller module 230 can be configured to prevent data receipt bythe network device 200 when outside of the transmission window 123rendering the network device 200 incapable of receiving data outside ofthe transmission window 123. In an example, the controller module 230can be configured to shutdown one or more components of the networkreceive chain 205 to prevent receipt of data outside of the transmissionwindow 123. In these examples, powering off the transmit or receivecomponents further reduces power consumption over merely keeping thesecomponents idle.

In an example, in response to transitioning back to the mains-powermode, the controller module 230 can be configured to again transmit datawithout regard to the transmission window 123. Thus, the controllermodule 230 controls the network device 200's power consumption duringlow-power operation by reducing some network performance and increasesnetwork performance when energy is less of a concern.

FIG. 3 illustrates an example of a method 300 for a network device 200to implement a synchronized network for battery backup.

At operation 305 the network device 200 establishes a synchronized sleepschedule 120 while in a mains-power mode of operation. The synchronizedsleep schedule 120 includes a transmission window 123. In an example,the synchronized sleep schedule 120 is shared with all participants ofthe network. That is, each network device 200 in the network receivesthe same synchronized sleep schedule 120 and adheres to the sametransmission window 123 for sending data. In an example, the networkdevice 200 receives synchronization messages 125 at regular intervals toestablish the synchronized sleep schedule 120 with the network.

At operation 310 the network device 200 transmits data in themains-power mode without regard for the transmission window 123.

At operation 315 the network device 200 detects an interruption of mainspower and transitions to a low-power mode of operation. In an example,the network device 200 is incapable of receiving data when it is in thelow-power mode. In an example, the network device 200 shuts down (e.g.,powers off) one or more components of its network receive chain 205(antennas, decoders, mixers, etc.). In an example, the network device200 notifies at least one another network participant of its transitionto the low-power mode.

At operation 320 the network device 200 transmits data in the low-powermode by restricting data transmission to the transmission window 123(i.e., not transmitting data outside of the transmission window 123). Inan example, the network device 200 restricts transmission by shuttingdown one or more components of its network transmit chain 210.

At operation 325 the network device 200 can optionally detectre-establishment of mains power and transition to the mains-power mode.In an example, the network device 200 notifies at least one othernetwork participant of its transition to the mains-power mode.

At operation 330 the network device 200, in response to the transitionof operation 325, will again transmit data in the mains-power modewithout regard to the transmission window 123. That is, after mainspower is restored, the network device 200 can resume the previoushigh-performance network operation.

FIG. 4 illustrates a block diagram of an example machine 400 upon whichany one or more of the techniques (e.g., methodologies) discussed hereinmay perform. In alternative embodiments, the machine 400 may operate asa standalone device or may be connected (e.g., networked) to othermachines. In a networked deployment, the machine 400 may operate in thecapacity of a server machine, a client machine, or both in server-clientnetwork environments. In an example, the machine 400 may act as a peermachine in peer-to-peer (P2P) (or other distributed) networkenvironment. The machine 400 may be a personal computer (PC), a tabletPC, a set-top box (STB), a personal digital assistant (PDA), a mobiletelephone, a web appliance, a network router, switch or bridge, or anymachine capable of executing instructions (sequential or otherwise) thatspecify actions to be taken by that machine. Further, while only asingle machine is illustrated, the term “machine” shall also be taken toinclude any collection of machines that individually or jointly executea set (or multiple sets) of instructions to perform any one or more ofthe methodologies discussed herein, such as cloud computing, software asa service (SaaS), other computer cluster configurations.

Examples, as described herein, may include, or may operate on, logic ora number of components, modules, or mechanisms. Modules are tangibleentities (e.g., hardware) capable of performing specified operations andmay be configured or arranged in a certain manner. In an example,circuits may be arranged (e.g., internally or with respect to externalentities such as other circuits) in a specified manner as a module. Inan example, the whole or part of one or more computer systems (e.g., astandalone, client or server computer system) or one or more hardwareprocessors may be configured by firmware or software (e.g.,instructions, an application portion, or an application) as a modulethat operates to perform specified operations. In an example, thesoftware may reside on a machine readable medium. In an example, thesoftware, when executed by the underlying hardware of the module, causesthe hardware to perform the specified operations.

Accordingly, the term “module” is understood to encompass a tangibleentity, be that an entity that is physically constructed, specificallyconfigured (e.g., hardwired), or temporarily (e.g., transitorily)configured (e.g., programmed) to operate in a specified manner or toperform part or all of any operation described herein. Consideringexamples in which modules are temporarily configured, each of themodules need not be instantiated at any one moment in time. For example,where the modules comprise a general-purpose hardware processorconfigured using software, the general-purpose hardware processor may beconfigured as respective different modules at different times. Softwaremay accordingly configure a hardware processor, for example, toconstitute a particular module at one instance of time and to constitutea different module at a different instance of time.

Machine (e.g., computer system) 400 may include a hardware processor 402(e.g., a central processing unit (CPU), a graphics processing unit(GPU), a hardware processor core, or any combination thereof), a mainmemory 404 and a static memory 406, some or all of which may communicatewith each other via an interlink (e.g., bus) 408. The machine 400 mayfurther include a display unit 410, an alphanumeric input device 412(e.g., a keyboard), and a user interface (UI) navigation device 414(e.g., a mouse). In an example, the display unit 410, input device 412and UI navigation device 414 may be a touch screen display. The machine400 may additionally include a storage device (e.g., drive unit) 416, asignal generation device 418 (e.g., a speaker), a network interfacedevice 420, and one or more sensors 421, such as a global positioningsystem (GPS) sensor, compass, accelerometer, or other sensor. Themachine 400 may include an output controller 428, such as a serial(e.g., universal serial bus (USB), parallel, or other wired or wireless(e.g., infrared (IR), near field communication (NFC), etc.) connectionto communicate or control one or more peripheral devices (e.g., aprinter, card reader, etc.).

The storage device 416 may include a machine readable medium 422 onwhich is stored one or more sets of data structures or instructions 424(e.g., software) embodying or utilized by any one or more of thetechniques or functions described herein. The instructions 424 may alsoreside, completely or at least partially, within the main memory 404,within static memory 406, or within the hardware processor 402 duringexecution thereof by the machine 400. In an example, one or anycombination of the hardware processor 402, the main memory 404, thestatic memory 406, or the storage device 416 may constitute machinereadable media.

While the machine readable medium 422 is illustrated as a single medium,the term “machine readable medium” may include a single medium ormultiple media (e.g., a centralized or distributed database, and/orassociated caches and servers) configured to store the one or moreinstructions 424.

The term “machine readable medium” may include any medium that iscapable of storing, encoding, or carrying instructions for execution bythe machine 400 and that cause the machine 400 to perform any one ormore of the techniques of the present disclosure, or that is capable ofstoring, encoding or carrying data structures used by or associated withsuch instructions. Non-limiting machine readable medium examples mayinclude solid-state memories, and optical and magnetic media. In anexample, a massed machine readable medium comprises a machine readablemedium with a plurality of particles having resting mass. Specificexamples of massed machine readable media may include: non-volatilememory, such as semiconductor memory devices (e.g., ElectricallyProgrammable Read-Only Memory (EPROM), Electrically ErasableProgrammable Read-Only Memory (EEPROM)) and flash memory devices;magnetic disks, such as internal hard disks and removable disks;magneto-optical disks; and CD-ROM and DVD-ROM disks.

The instructions 424 may further be transmitted or received over acommunications network 426 using a transmission medium via the networkinterface device 420 utilizing any one of a number of transfer protocols(e.g., frame relay, internet protocol (IP), transmission controlprotocol (TCP), user datagram protocol (UDP), hypertext transferprotocol (HTTP), etc.). Example communication networks may include alocal area network (LAN), a wide area network (WAN), a packet datanetwork (e.g., the Internet), mobile telephone networks (e.g., cellularnetworks), Plain Old Telephone (POTS) networks, and wireless datanetworks (e.g., Institute of Electrical and Electronics Engineers (IEEE)802.11 family of standards known as Wi-Fi®, IEEE 802.16 family ofstandards known as WiMax®), IEEE 802.15.4 family of standards,peer-to-peer (P2P) networks, among others. In an example, the networkinterface device 420 may include one or more physical jacks (e.g.,Ethernet, coaxial, or phone jacks) or one or more antennas to connect tothe communications network 426. In an example, the network interfacedevice 420 may include a plurality of antennas to wirelessly communicateusing at least one of single-input multiple-output (SIMO),multiple-input multiple-output (MIMO), or multiple-input single-output(MISO) techniques. The term “transmission medium” shall be taken toinclude any intangible medium that is capable of storing, encoding orcarrying instructions for execution by the machine 400, and includesdigital or analog communications signals or other intangible medium tofacilitate communication of such software.

Additional Notes & Examples

Example 1 can include subject matter (such as a method, means forperforming acts, or machine readable medium including instructions that,when performed by a machine cause the machine to performs acts)performed by a network device in a network comprising establishing asynchronized sleep schedule with the network, transmitting data in amains-power mode of operation without regard for a transmission windowof the synchronized sleep schedule, detecting an interruption of mainspower to the network device and transitioning the network device to alow-power mode of operation, and transmitting data in the low-powermode, the low-power mode restricting data transmission to thetransmission window of the synchronized sleep schedule.

In Example 2, the subject matter of Example 1 can optionally includewherein the low-power mode restricting data transmission to thetransmission window of the synchronized sleep schedule includes shuttingdown a network transmit chain.

In Example 3, the subject matter of one or both of Examples 1 or 2 canoptionally include the network device being incapable of receiving datawhen it is in low-power mode.

In Example 4, the subject matter of Example 3 can optionally include thenetwork device shutting down a network receive chain in the low-powermode.

In Example 5, the subject matter of one or more of Examples 1-4 canoptionally include wherein the synchronized sleep schedule is sharedwith all participants of the network.

In Example 6, the subject matter of one or more of Examples 1-5 canoptionally include wherein transitioning the network device to thelow-power mode of operation includes notifying another networkparticipant of the transition.

In Example 7, the subject matter of one or more of Examples 1-6 canoptionally include detecting re-establishment of mains power to thenetwork device and transitioning the network device to the mains-powermode of operation, and transmitting data in the mains-power mode ofoperation.

In Example 8, the subject matter of Example 6 can optionally includewherein transitioning the network device to the mains-power mode ofoperation includes notifying another network participant of thetransition to mains power.

In Example 9, the subject matter of one or more of Examples 1-8 canoptionally include wherein establishing the synchronized sleep schedulewith the network includes receiving synchronization messages at regularintervals.

Example 10 can include, or can optionally be combined with the subjectmatter of one or more of Examples 1-9 to include, subject matter (suchas a method, means for performing acts, or machine readable mediumincluding instructions that, when performed by a machine cause themachine to performs acts) comprising establishing a synchronized sleepschedule with a network, transmitting data in a mains-power mode ofoperation without regard for a transmission window of the synchronizedsleep schedule, detecting an interruption of mains power to the networkdevice and transitioning the network device to a low-power mode ofoperation, and transmitting data in the low-power mode, the low-powermode restricting data transmission to the transmission window of thesynchronized sleep schedule.

In Example 11, the subject matter of Example 10 can optionally includewherein the low-power mode restricting data transmission to thetransmission window of the synchronized sleep schedule includes shuttingdown a network transmit chain.

In Example 12, the subject matter of one or both of Examples 10 and 11can optionally include wherein the network device is incapable ofreceiving data when it is in the low-power mode.

In Example 13, the subject matter of Example 12 can optionally includewherein the network device shuts down a network receive chain in thelow-power mode.

In Example 14, the subject matter of one or more of Examples 10-13 canoptionally include wherein the synchronized sleep schedule is sharedwith all participants of the network.

In Example 15, the subject matter of one or more of Examples 10-14 canoptionally include wherein transitioning the network device to thelow-power mode of operation includes notifying another networkparticipant of the transition.

In Example 16, the subject matter of one or more of Examples 10-15 canoptionally include (e.g., instructions causing the machine to performoperations comprising) detecting re-establishment of mains power to thenetwork device and transitioning the network device to the mains-powermode of operation, and transmitting data in the mains-power mode ofoperation.

In Example 17, the subject matter of Example 16 can optionally includewherein transitioning the network device to the mains-power mode ofoperation includes notifying another network participant of thetransition to mains power.

In Example 18, the subject matter of one or more of Examples 10-17 canoptionally include wherein establishing the synchronized sleep schedulewith the network includes receiving synchronization messages at regularintervals.

Example 19 can include, or can optionally be combined with the subjectmatter of one or more of Examples 1-18 to include, subject matter (suchas a device, apparatus, or network device in a network) comprising anetwork transmit chain arranged to transmit data to the network, anetwork receive chain arranged to receive data from the network, a powermode detection module arranged to determine whether the network deviceis operating in at least one of a low-power mode or a mains-poweredmode, a synchronization module configured to receive and storesynchronization information via the network receive chain, thesynchronization information including a synchronized sleep schedule forthe network, and a controller module. The controller module can bearranged to transmit data via the network transmit chain without regardto a transmission window of the synchronized sleep schedule when thepower mode detection module determines that the network device isoperating in the mains-powered mode, and restrict data transmission viathe network transmit chain to the transmission window when the powermode detection module determines that the network device is operating inthe low-powered mode.

In Example 20, the subject matter of Example 19 can optionally includewherein to determine whether the network device is operating in at leastone of the low-power mode or the mains-powered mode includes the powermode detection module arranged to monitor a source voltage of thenetwork device for transitions over a predetermined source voltagethreshold.

In Example 21, the subject matter of one or both of Examples 19 and 20can optionally include wherein to determine whether the network deviceis operating in at least one of the low-power mode or the mains-poweredmode includes the power mode detection module arranged to monitor asleep request control line of the network device for the presence of asleep assertion.

In Example 22, the subject matter of one or more of Examples 19-21 canoptionally include wherein to determine whether the network device isoperating in at least one of the low-power mode or the mains-poweredmode includes the power mode detection module arranged to monitor datareceived from the network receive chain for at least one of a sleep orwake command.

In Example 23, the subject matter of one or more of Examples 19-22 canoptionally include wherein the synchronized sleep schedule is sharedwith all participants of the network.

In Example 24, the subject matter of one or more of Examples 19-23 canoptionally include wherein to restrict data transmission via the networktransmit chain to the transmission window the controller module isconfigured to shutdown the network transmit chain.

Example 25 can include, or can optionally be combined with the subjectmatter of one or more of Examples 1-24 to include, subject matter (suchas a system or network) comprising a synchronized sleep schedule, afirst network device and a second network device. The first networkdevice can be in low-power mode and arranged to maintain, within thefirst network device, the synchronized sleep schedule without regard toa current power mode of the first network device, the synchronized sleepschedule including a transmission window, and restrict datatransmission, to the network, to the transmission window. The secondnetwork device can be arranged to transmit data to the first networkdevice.

In Example 26, the subject matter of Example 25 can optionally includewherein the first network device is arranged to notify the network whentransitioning into the low-power mode, and the second network device isarranged to transition into the lower-power mode in response to amessage based on the notification from the first network device.

In Example 27, the subject matter of Example 26 can optionally includewherein every network device in the network is arranged to transitioninto the low-power mode in response to the message.

In Example 28, the subject matter of one or more of Examples 25-27 canoptionally include wherein the network is a mesh network.

In Example 29, the subject matter of one or more of Examples 25-28 canoptionally include wherein the first network device is a mesh router ofthe second network device, the second network device is in a mains-powermode, and the second network device is arranged to cease using the firstnetwork device as the wireless mesh router in response to adetermination that the first network device is in a low-power mode.

In Example 30, the subject matter of one or more of Examples 25-29 canoptionally include wherein the network is a synchronized sleep networkarranged to communicate the synchronized sleep schedule to every networkdevice in the network, the synchronized sleep schedule including asingle set of transmission windows for every network device, thetransmission window being a member of the set of transmission windows.

In Example 31, the subject matter of one or both of Examples 29 and 30can optionally include wherein the network is arranged to transmithigher priority data during a transmission window in the set oftransmission windows.

The above detailed description includes references to the accompanyingdrawings, which form a part of the detailed description. The drawingsshow, by way of illustration, specific embodiments in that may bepracticed. These embodiments are also referred to herein as “examples.”Such examples can include elements in addition to those shown ordescribed. However, the present inventors also contemplate examples inwhich only those elements shown or described are provided. Moreover, thepresent inventors also contemplate examples using any combination orpermutation of those elements shown or described (or one or more aspectsthereof), either with respect to a particular example (or one or moreaspects thereof), or with respect to other examples (or one or moreaspects thereof) shown or described herein.

All publications, patents, and patent documents referred to in thisdocument are incorporated by reference herein in their entirety, asthough individually incorporated by reference. In the event ofinconsistent usages between this document and those documents soincorporated by reference, the usage in the incorporated reference(s)should be considered supplementary to that of this document; forirreconcilable inconsistencies, the usage in this document controls.

In this document, the terms “a” or “an” are used, as is common in patentdocuments, to include one or more than one, independent of any otherinstances or usages of “at least one” or “one or more.” In thisdocument, the term “or” is used to refer to a nonexclusive or, such that“A or B” includes “A but not B,” “B but not A,” and “A and B,” unlessotherwise indicated. In the appended claims, the terms “including” and“in which” are used as the plain-English equivalents of the respectiveterms “comprising” and “wherein.” Also, in the following claims, theterms “including” and “comprising” are open-ended, that is, a system,device, article, or process that includes elements in addition to thoselisted after such a term in a claim are still deemed to fall within thescope of that claim. Moreover, in the following claims, the terms“first,” “second,” and “third,” etc. are used merely as labels, and arenot intended to impose numerical requirements on their objects.

The above description is intended to be illustrative, and notrestrictive. For example, the above-described examples (or one or moreaspects thereof) may be used in combination with each other. Otherembodiments can be used, such as by one of ordinary skill in the artupon reviewing the above description. The Abstract is to allow thereader to quickly ascertain the nature of the technical disclosure, forexample, to comply with 37 C.F.R. §1.72(b) in the United States ofAmerica. It is submitted with the understanding that it will not be usedto interpret or limit the scope or meaning of the claims. Also, in theabove Detailed Description, various features may be grouped together tostreamline the disclosure. This should not be interpreted as intendingthat an unclaimed disclosed feature is essential to any claim. Rather,inventive subject matter may lie in less than all features of aparticular disclosed embodiment. Thus, the following claims are herebyincorporated into the Detailed Description, with each claim standing onits own as a separate embodiment. The scope of the embodiments should bedetermined with reference to the appended claims, along with the fullscope of equivalents to which such claims are entitled.

What is claimed is:
 1. A method performed by a network device in anetwork, the method comprising: establishing a synchronized sleepschedule with the network; transmitting data in a mains-power mode ofoperation without regard for a transmission window of the synchronizedsleep schedule; detecting an interruption of mains power to the networkdevice and transitioning the network device to a low-power mode ofoperation; and transmitting data in the low-power mode, the low-powermode restricting data transmission to the transmission window of thesynchronized sleep schedule.
 2. The method of claim 1, wherein thelow-power mode restricting data transmission to the transmission windowof the synchronized sleep schedule includes shutting down a networktransmit chain.
 3. The method of claim 1, wherein the network device isincapable of receiving data when it is in low-power mode.
 4. The methodof claim 3, wherein the network device shuts down a network receivechain in the low-power mode.
 5. The method of claim 1, wherein thesynchronized sleep schedule is shared with all participants of thenetwork.
 6. The method of claim 1, wherein transitioning the networkdevice to the low-power mode of operation includes notifying anothernetwork participant of the transition.
 7. The method of claim 1,comprising: detecting re-establishment of mains power to the networkdevice and transitioning the network device to the mains-power mode ofoperation; and transmitting data in the mains-power mode of operation.8. The method of claim 7, wherein transitioning the network device tothe mains-power mode of operation includes notifying another networkparticipant of the transition to mains power.
 9. The method of claim 1,wherein establishing the synchronized sleep schedule with the networkincludes receiving synchronization messages at regular intervals.
 10. Amachine readable medium including instructions that, when executed by acomponent of a machine, cause a network device to perform operationscomprising: establishing a synchronized sleep schedule with a network;transmitting data in a mains-power mode of operation without regard fora transmission window of the synchronized sleep schedule; detecting aninterruption of mains power to the network device and transitioning thenetwork device to a low-power mode of operation; and transmitting datain the low-power mode, the low-power mode restricting data transmissionto the transmission window of the synchronized sleep schedule.
 11. Themachine readable medium of claim 10, wherein the low-power moderestricting data transmission to the transmission window of thesynchronized sleep schedule includes shutting down a network transmitchain.
 12. The machine readable medium of claim 10, wherein the networkdevice is incapable of receiving data when it is in the low-power mode.13. The machine readable medium of claim 12, wherein the network deviceshuts down a network receive chain in the low-power mode.
 14. Themachine readable medium of claim 10, wherein the synchronized sleepschedule is shared with all participants of the network.
 15. The machinereadable medium of claim 10, wherein transitioning the network device tothe low-power mode of operation includes notifying another networkparticipant of the transition.
 16. The machine readable medium of claim10, including instructions causing the machine to perform operationscomprising: detecting re-establishment of mains power to the networkdevice and transitioning the network device to the mains-power mode ofoperation; and transmitting data in the mains-power mode of operation.17. The machine readable medium of claim 16, wherein transitioning thenetwork device to the mains-power mode of operation includes notifyinganother network participant of the transition to mains power.
 18. Themachine readable medium of claim 10, wherein establishing thesynchronized sleep schedule with the network includes receivingsynchronization messages at regular intervals.
 19. A network device in anetwork, the network device comprising: a network transmit chainarranged to transmit data to the network; a network receive chainarranged to receive data from the network; a power mode detection modulearranged to determine whether the network device is operating in atleast one of a low-power mode or a mains-powered mode; a synchronizationmodule configured to receive and store synchronization information viathe network receive chain, the synchronization information including asynchronized sleep schedule for the network; and a controller modulearranged to: transmit data via the network transmit chain without regardto a transmission window of the synchronized sleep schedule when thepower mode detection module determines that the network device isoperating in the mains-powered mode; and restrict data transmission viathe network transmit chain to the transmission window when the powermode detection module determines that the network device is operating inthe low-powered mode.
 20. The network device of claim 19, wherein todetermine whether the network device is operating in at least one of thelow-power mode or the mains-powered mode includes the power modedetection module arranged to monitor a source voltage of the networkdevice for transitions over a predetermined source voltage threshold.21. The network device of claim 19, wherein to determine whether thenetwork device is operating in at least one of the low-power mode or themains-powered mode includes the power mode detection module arranged tomonitor a sleep request control line of the network device for thepresence of a sleep assertion.
 22. The network device of claim 19,wherein to determine whether the network device is operating in at leastone of the low-power mode or the mains-powered mode includes the powermode detection module arranged to monitor data received from the networkreceive chain for at least one of a sleep or wake command.
 23. Thenetwork device of claim 19, wherein the synchronized sleep schedule isshared with all participants of the network.
 24. The network device ofclaim 19, wherein to restrict data transmission via the network transmitchain to the transmission window the controller module is configured toshutdown the network transmit chain.
 25. A system comprising a networkincluding: a synchronized sleep schedule; a first network device inlow-power mode arranged to: maintain, within the first network device,the synchronized sleep schedule without regard to a current power modeof the first network device, the synchronized sleep schedule including atransmission window; and restrict data transmission, to the network, tothe transmission window; and a second network device arranged totransmit data to the first network device.
 26. The system of claim 25,wherein the first network device is arranged to notify the network whentransitioning into the low-power mode; and the second network device isarranged to transition into the lower-power mode in response to amessage based on the notification from the first network device.
 27. Thesystem of claim 26, wherein every network device in the network isarranged to transition into the low-power mode in response to themessage.
 28. The system of claim 25, wherein the network is a meshnetwork.
 29. The system of claim 25, wherein the first network device isa mesh router of the second network device, the second network device isin a mains-power mode, and the second network device is arranged tocease using the first network device as the wireless mesh router inresponse to a determination that the first network device is in alow-power mode.
 30. The system of claim 25, wherein the network is asynchronized sleep network arranged to communicate the synchronizedsleep schedule to every network device in the network, the synchronizedsleep schedule including a single set of transmission windows for everynetwork device, the transmission window being a member of the set oftransmission windows.
 31. The system of claim 29, wherein the network isarranged to transmit higher priority data during a transmission windowin the set of transmission windows.